Guide for Selection of Spiral Chutes
Facing 318 different specifications of spiral chutes, what’s the optimum option method? The common methods are:
1.Selection based on Technology
With help from the Company people, selecting 2-3 specifications of spiral chutes according to technical performance; estimating numbers of spiral chutes according to throughput and processing stages.
2.Selection based on testing?
With help from the Company people, for preliminary selected spiral chutes, pilot tests with ore samples delivered by the customers will be done in the Company’s pilot plant or other R&D institutes. Based on the test results and observation, comparison and analysis on the concentration of ore samples, the final selection of the desired spiral chutes will be determined.

Principles for Selection Spiral Chutes based on Technology
1.Selecting diameter series based on particle size, throughput and space area occupied?
If the ore particle size is coarser, larger throughput, and the space is limited, bigger diameter should be selected, but it is not always. For example, In a Canadian iron mine, several thousands of spiral chutes are used in concentration of hematite, all spiral chutes areф600 spirals. Spirals in small diameter are easy for assembly? and disassembly. Small size is beneficial for 2-layer or 3-layer configuration. The improvement for process flowsheet is flexible, especially for recovery of finely disseminated minerals.
General rules are, larger diameter spiral chutes is commonly for coarser particles; and smaller ones with a gentle flow, suitable for recovery of fine particles. ф600 smaller spirals can effectively recovers particle size up to 37-19 microns, similar to the particle size range of Yunxi centrifugal concentrators, and the throughput is same as that of a slime table.
2.Selecting spiral space series based on difficulty of concentration and operation stages
Model 75 spiral space can be used for easy beneficiated ore. And Model 45 type can be used for ore difficult to be treated. With same spiral space, Model 75 is higher in throughput and better concentration ratio than Model 60 and 45. But Model 60 is commonly used. In general, Model 60 is better for rougher, Model 75 for cleaner, Model 45 for scavenger.
3.Selecting special chute surface based on recovery purpose and ore particle size
If the beneficiation purpose is for tailing removal, the stronger grooved and rifled chute surface can be used. The grooved type is suitable for finer material, rifled type is better for use to treat coarser material. Both are beneficial for increasing concentrate yield and recovery.? For the purpose for concentration is to increasing the concentrate grade, the smooth chute surface ones can be selected. For gold and coal, special ones chute surface can be used.